The present invention relates to a composition containing a fluorine-containing compound and giving a non-tackiness between articles. The present invention also relates to an anti-blocking agent, wire stripping agent and mold release agent comprising said composition as an active component.
A material preventing the adhesion between the same materials or between different materials is required. For instance, in the case of the preparation of a shaped product made of, for example, cement, ceramics, or a polymeric material such as a synthetic resin or rubber, a mold release agent is frequently used in order to easily demold the shaped product from a (metal) mold.
In a coaxial cable having a shield layer formed from the braided metal small-gage wires on insulated electrical wire, an easy terminal treatment operation is desired by increasing a separation property between the shield layer and the insulated electrical wire. Also in the case of a cable prepared by applying a protective coating to several associated insulated electrical wires, a good separation property between the insulated electrical wires and the protective coating is important for the easy terminal treatment operation.
When rubber materials before or after the vulcanization are piled, the rubber materials adhere to each other due to the tackiness of the rubber materials themselves so that it is difficult to peel one rubber material from the other rubber material. Namely, a blocking phenomenon arises. In order to prevent the blocking phenomenon, it is necessary to use an anti-blocking agent in many cases.
For example, a natural or synthetic compound such as a silicone oil, a mineral oil, a paraffin wax, a fatty acid derivative and a glycol and an inorganic material such as talc and mica and the like are conventionally used as a mold release agent used for an easy separation from the mold during the molding process of the polymeric material and the like. Generally these mold release agents are coated on the mold before introducing the molded product in the mold. When a mold release life is short, the mold release agent is usually coated on the mold every molding process.
It is difficult to coat homogeneously the inorganic material such as talc and mica on the mold so that the inorganic material suffers from an insufficient mold releasability and a bad operation environment due to the scatter of powder.
The silicone oil is the most universally used mold release agent because of the good mold releasability. When the silicone oil is used for molding a material having a strong adhesion property such as a urethane or epoxy resin, it is necessary to coat the mold with the large amount of the silicone oil having an improved strength of a mold release agent film by the addition of fine powder such as silicon oxide. The large amount of the coating gives the migration of the mold release agent to the molded product so that it is difficult to conduct a post-treatment of a surface of the molded product, for example, a coating or adhesion treatment. In addition, the large amount of the coating is economically disadvantageous.
When the molding process is continued by coating the large amount of the mold release agent on the same mold, the tailings of the mold release agent or molded product remain on a mold surface and the mold must be often washed so as to decrease the efficiency of molding process.
A mold release agent comprising a phosphate ester of an alcohol having a perfluoroalkyl group and a silicone oil is known (cf. Japanese Patent Kokoku Publication No. 23270/1978) and is useful as a mold release agent for a resin having a high tackiness such as an epoxy resin.
However, when the mold release agent described in the above Publication is used as a stripping agent for facilitating a terminal processing operation of an electrical wire or an anti-blocking agent for a vulcanized or unvulcanized rubber, said mold release agent gives insufficient effect. The silicone oil and the inorganic material such as talc and mica also give insufficient effect. Talc and mica have the same problem as in the use of the mold release agent in addition to the insufficient effect.
An object of the present invention is to provide an abherent composition which can be used as a mold release agent, a stripping agent for an electrical wire and an anti-blocking agent for a synthetic resin and a vulcanized or unvulcanized rubber.
A gist of the present invention resides in a composition giving a abherent property to a substrate and comprising
(A) a compound having a C4-C20 perfluoro-alkyl or alkenyl group,
(B) polytetrafluoroethylene having a number-average molecular weight of at most 500,000, and
(C) at least one compound selected from the group consisting of a silicone oil, a silicone resin and a highly fluorinated compound having a boiling point of at least 100xc2x0 C. (except those included in the components (A) and (B)).
The other gist of the present invention resides in an anti-blocking agent, a stripping agent for an electrical wire and a mold release agent which contain said composition as an active component.
Hereinafter, the present invention will be explained in detail.
Examples of the compound having the C4-C20 perfluoro-alkyl or alkenyl group which is one component of the composition according to the present invention are a phosphate ester or a salt thereof, a phosphonic acid derivative and a phosphinic acid derivative having a C4-C20 perfluoro-alkyl or alkenyl group, and a homopolymer or copolymer of a monosubstituted ethylene or a (meth)acrylate ester having a C4-C20 perfluoro-alkyl or alkenyl group. The phosphate ester or salt thereof having the perfluoro-alkyl or alkenyl group is particularly preferable.
The preferable example of the perfluoro-alkyl or alkenyl group-containing phosphate ester or salt thereof used in the present invention is a compound having the following formula in which one or two hydrogen atom of three hydroxyl groups in phosphoric acid (orthophosphoric acid, a chemical formula: H3PO4 or PO(OH)3) is substituted with an organic group having C4-C20 perfluoro-alkyl group:
(RfRO)nPO(OH)3xe2x88x92n
wherein Rf is a C4-C20 perfluoroalkyl group,
n is an integer of 1 to 2,
R is a divalent organic group of the formula: xe2x80x94CH2CH(Z)CmH2mxe2x80x94 or xe2x80x94SO2N(Rxe2x80x2)ClH2lxe2x80x94
(wherein Z is H, CH3, C2H5, Cl or ORxe2x80x3 (Rxe2x80x3 is H, CH3, C2H5, COCH3, COC2H5 or xe2x80x94CH2COOH or a salt thereof), m is an integer of 0 or 1-4, Rxe2x80x2 is a C1-C4 alkyl group, and l is an integer of 1-4, or salt thereof. Specific examples of the salt are an alkaline metal salt, an ammonium salt and an amine salt.
Particularly preferable perfluroalkyl group-containing phosphate ester is the perfluoroalkyl group-containing phosphate ester having the above formula in which Rf is a C7-C20 perfluoroalkyl group, R is an alkylene group, a xe2x80x94CH2CH(Z)CmH2mxe2x80x94 group (wherein Z is OH or xe2x80x94OCOCH3) or xe2x80x94SO2N(Rxe2x80x2)ClH2lxe2x80x94 (wherein Rxe2x80x2 is CH3 or C2H5).
Specific examples of the perfluoroalkyl group-containing phosphate ester are as follows:
(A) [(CF3)2CF(CF2CF2) iCH2CH(OH)CH2O]nPO(OH)3xe2x88x92n (wherein i is an integer of at least 1)
(B) [C8F17SO2N(C2H5) CH2CH2O]nPO(OH)3xe2x88x92n 
(C) (C7F15CH2CH2O)nPO(OH)3xe2x88x92n 
(D) (CF3)2CF(CF2CF2)iCH2CH2CH2OPO(OH)2 (wherein i is an integer of at least 1)
(E) (CF3)2CF(CF2CF2)3CH2CH(Cl)CH2OPO(OH)2 
(F) (CF3)2CF(CF2CF2)3CH2CH(CH3)OPO(OH)2 
(G) (CF3)2CF(CF2CF2)3CH2CH(OCH2COOH)CH2OPO(OH)2 
The perfluoro-alkyl or alkenyl group-containing phosphate ester and salt thereof used in the present invention can be used alone or in combination of at least two.
The perfluoro-alkyl or alkenyl group-containing phosphonic acid derivative or phosphinic acid derivative used in the present invention is preferably of the formula: 
wherein Rf is a C4-C20 perfluoroalkyl or perfluoroalkenyl group, R1 is a hydrogen atom, an alkaline metal atom, an ammonium group or a C1-C5 alkyl group, R2 is a C1-C10 alkylene or xe2x80x94CH2CH(OR3)CH2xe2x80x94 group (R3 is a hydrogen atom or a C1-C10 alkyl group), and each of j, k and l is an integer provided that jxe2x89xa71, kxe2x89xa70, lxe2x89xa70, and j+k+l=3, or the formula: 
wherein Rf and R1 are as defined above, and each of k and l is an integer provided that kxe2x89xa70, lxe2x89xa70and k+l=2.
The above phosphonic acid derivative or phosphinic acid derivative may be used in the form of a salt. Specific examples of the salt are the same as in the case of the phosphate ester.
Specific examples of the phosphonic acid derivative or phosphinic acid derivative are as follows: 
The perfluoro-alkyl or alkenyl group-containing phosphonic acid derivative or phosphinic acid derivative or salt thereof used in the present invention is used alone or in combination of at least two.
The homopolymer or copolymer of the perfluoro-alkyl or alkenyl group-containing mono-substituted ethylene or (meth)acrylate ester used in the present invention includes a homopolymer of one of the above monomers, a copolymer of at least two above monomers, and a copolymer of one of the above monomers with another copolymerizable monomer. Specific examples of the perfluoro-alkyl or alkenyl group-containing mono-substituted ethylene or (meth)acrylate ester are the following compounds of the formulas (1)-(5): 
wherein Rf is a C4-C20 perfluoroalkyl group or perfluoroalkenyl group, R1 is a hydrogen atom or a methyl group, R2 is a C1-C10 alkylene group or a xe2x80x94CH2CH(OR3)CH2xe2x80x94 group, R3 is a hydrogen atom or a C1-C10 alkyl group, and R4 is a C1-C10 alkylene group.
Specific examples of the fluorine-containing compounds of the formulas (1)-(5) are as follows: 
Specific examples of the monomer copolymerizable with the above monomers are methyl, ethyl, propyl, butyl, cyclohexyl, benzyl, octyl, 2-ethylhexyl, lauryl, tridecyl, cetyl, stearyl, methoxyethyl, ethoxyethyl, butoxyethyl, methoxypolyethylene glycol, 2-hydroxyethyl, 2-hydroxy-3-chloropropyl, diethylaminoethyl, glycidyl and tetrahydrofurfuryl esters of acrylic acid or methacrylic acid, acrylamide, methacrylamide, monovalent organic acid vinyl ester having 2 to 18 carbon atoms, a C1-C18 alkyl vinyl ether, vinyl chloride, vinylidene chloride, acrylonitrile, methacrylonitrile, (meth)acroxypropyltrimethoxysilane and the like.
Any of conventional polymerization procedures can be used and the conditions of the polymerization reaction can arbitrarily selected so as to give the homopolymer or copolymer of the perfluoroalkyl or perfluoroalkenyl group-containing mono-substituted ethylene or (meth)acrylate ester, or the copolymer thereof with the copolymerizable monomer. Specific examples of the polymerization procedure are a solution polymerization, an emulsion polymerization, a suspension polymerization, a bulk polymerization and the like. Firstly, a monomer selected from the perfluoroalkyl or perfluoroalkenyl group-containing mono-substituted ethylene and/or (meth)acrylate ester, and optionally the copolymerizable monomer are dissolved in a suitable organic solvent (the solution polymerization) or dispersed in water by the use of an emulsifier (the emulsion polymerization). Then, a polymerization initiation source such as a peroxide, an azo compound and an ionized radiation is applied to the solution or dispersion to give a polymer. The organic solvent is not limited, and may be, for example, a halogenated hydrocarbon solvent such as methylchloroform, tetrachlorodifluoroethane, 1,1,2-trichloro-1,2,2-trifluoroethane, trichloroethylene and tetrachloroethylene. An average molecular weight of the resultant polymer is from 2,000 to 60,000. An amount of the perfluoroalkyl or perfluoroalkenyl group-containing mono-substituted ethylene or (meth)acrylate ester is preferably at least 30 % by weight based on a total amount of the perfluoro-alkyl or alkenyl group-containing mono-substituted ethylene or (meth)acrylate ester and the copolymerizable monomer. The amount is preferably at least 60% by weight.
The abherent composition of the present invention contains polytetrafluoroethylene. The number-average molecular weight of polytetrafluoroethylene is at most 500,000, preferably from 50,000 to 300,000. If the number-average molecular weight is higher than 500,000, the composition had no good non-tackiness.
The amount of polytetrafluoroethylene is from 0.1 to 30 parts by weight, preferably from 0.5 to 20 parts by weight per 1 part by weight of the perfluoro-alkyl or alkenyl group-containing compound (A). If the amount is larger than 30 parts by weight, the composition has no good non-tackiness. If the amount is smaller than 0.1 parts by weight, the composition exhibits no non-tackiness.
The composition of the present invention contains at least one compound selected from the group consisting of the silicone oil, the silicone resin and the highly fluorinated compound having the boiling point of at least 100xc2x0 C. (except the compounds included in the components (A) and (B)).
The silicone oil used in the present invention is preferably a non-curable polysiloxane having a side chain of a C1-C5 alkyl group, a C1-C5 fluoroalkyl group, a phenyl group and the like which is a liquid or semisolid at a room temperature.
The silicone resin used in the present invention may be widely used conventional one and may be, for example, a methylsilicone varnish. The methylsilicone varnish is a copolymer having various repeating units of SiO2, CH3SiO3/2, (CH3)2SiO, (CH3)3SiO1/2 or the like and having a three-dimensional network. The copolymer may or may not have a crosslinkable group (for example, a hydroxyl group).
Specific examples of the highly fluorinated compound having a boiling point of at least 100xc2x0 C. are those except the compound (A) and compound (B) and are preferably a polychlorotrifluoroethylene or perfluoropolyether oil having a repeating unit of the formula:
xe2x80x94(CF2CFCl)nxe2x80x94
(wherein n is 2 to 15) 
or
xe2x80x94(CF2CF2CF2xe2x80x94O)nxe2x80x94
(wherein n is 2 to 200).
Specific examples of the highly fluorinated compound are Krytox (manufactured by Du Pont), Fomblin (manufactured by Montefluos), Daifloil (manufactured by Daikin Industries Ltd.) and Demnum (manufactured by Daikin Industries Ltd.).
The compound (C) is used in an amount of 0.05 to 10 parts by weight, preferably 0.2 to 5 parts by weight per 1 part by weight of the perfluoro-alkyl or alkenyl group-containing compound (A). If the amount is larger than 10 parts by weight, an adherend has a high stickiness so that the post-treatment cannot be conducted. If the amount is smaller than 0.2 parts by weight, the composition does not have the slipperiness required for an abhesive agent.
Each component of the composition is dissolved, dispersed or emulsified in a medium of water or an organic solvent to give a liquid.
Specific examples of the organic solvent used as the medium are alcohols such as methanol, ethanol, propanol and isopropanol; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ethers such as ethyl ether, isopropyl ether, dioxane and tetrahydrofuran; esters such as ethyl acetate and butyl acetate; halogenated hydrocarbons such as carbon tetrachloride, methylene chloride, ethylene chloride, trichloroethylene, perchloroethylene, trichloroethane, trichlorotrifluoroethane, tetrachlorodifluoroethane. The organic solvent may be used alone or in combination.
When water is used as the medium, a surfactant is used for dispersing or emulsifying each component in water. Suitable surfactant may be any of usual anionic, cationic, nonionic and amphoteric surfactants and is not limited. Specific examples of various surfactants are as follows:
Anionic Surfactant:
a higher fatty acid alkaline salt, an alkylsulfate salt, an alkylsulfonic acid salt,
an alkylarylsulfonic acid salt, an alkylphosphoric acid ester, a fluorine-containing carboxylic acid, a fluorine-containing sulfonic acid and the like
Cationic Surfactant:
a higher amine halogen-containing acid salt, a halogenated alkyl pirydinium,
a quaternary ammonium salt, a polyoxyethylenealkylamine and the like
Nonionic Surfactant:
a polyoxyethylenealkyl ether, a polyoxyethylenealkyl ester, a sorbitanalkyl ester, a sugar ester and the like
Amphoteric Surfactant:
a secondary, tertiary or quaternary ammonium salt and the like including betaine and imidazoline types
A carboxylic acid, a sulfate ester, a sulfonic acid and a phosphoric acid ester are useful as an anionic group.
The abherent composition of the present invention can be coated on a surface of a resin, a fiber, a rubber, a paper, a metal, a ceramic and the like and can prevent the adhesion between these materials. For example, each component of the composition of the present invention is dissolved, dispersed or emulsified in the medium of water or organic solvent to prepare a liquid, and the liquid is coated on a substrate by a conventional procedure such as the dipping, the spraying, the brush coating and the coating with an impregnated fabric and then usually dried to remove the medium (water or organic solvent). The amount of coating is 2 to 100 g/m2, preferably from 5 to 50 g/m2 in solid.
The composition of the present invention can be used for the prevention of adhesion between different kind of materials in addition to the prevention of adhesion between the same kind of materials. Preferable examples of the combination of the substrates coated with the composition of the present invention are the combination of the same kind materials, the combination of a resin and a metal, the combination of a rubber and a ceramic, the combination of a rubber and a metal, the combination of a metal and a ceramic and the like. The composition of the present invention is particularly useful as a mold release agent for molding a shaped article, a stripping agent for an electrical wire and an anti-blocking agent for a synthetic resin or a vulcanized or unvulcanized rubber.